Field of the Invention
The subject matter disclosed herein relates to improvements to baseplates for supporting rotating machinery. More specifically, the disclosure refers to baseplates for mounting and supporting systems comprising a turbine, e.g. a gas turbine, and a load, e.g. a centrifugal compressor, a pump or an electric generator with or without a speed reducer or multiplier load gear.
Description of the Related Art
In several industrial applications, for example in the gas and oil field, LNG applications and the like, it is required to support heavy machinery on a baseplate in such a manner that all the loads are adequately supported and torque generated by the machinery, also in case of sudden instantaneous failure of a driven load, can be resisted.
Typical rotating machinery which requires support on a baseplate or skid includes, but is not limited to gas turbines, electric generators, turbo compressors, such as centrifugal turbo compressors and the like.
Oil rigs and offshore platforms are often equipped with one or more gas turbines driving a load, such as an electric generator which provides electric power for the facilities of the rig.
Conventionally the rotating machinery mentioned above is mounted on a baseplate, or skid, which is secured to a deck of the platform after being leveled by suitable shims or packagings. The baseplate is dimensioned so as to withstand the static and dynamic loads generated by the machinery supported by the baseplate.
The rotating machinery arranged on the baseplate is provided with a plurality of auxiliary facilities, devices and skids including for example a fuel skid, a starter, lubricating oil circuit and relevant apparatus and devices, such as oil pumps, oil tanks and oil filters. Electric control panels are also provided, where the electronics required for controlling the rotating machines are arranged. The equipment mentioned above is by way of example of a wide range of possible auxiliaries and facilities which are required for the correct operation of the rotating machinery mounted on the baseplate.
The rotating machines as well as the auxiliaries thereof are usually arranged on a machine support platform, which is provided with a torsional resisting member and connected therewith in a torque transmitting relationship.
The rotating machinery and the auxiliaries, or at least part thereof, are usually contained in a turbine package.
The footprint of the baseplate must be sufficiently large to accommodate the above mentioned apparatus and this contributes to increasing the overall dimension of the baseplate. Access to the auxiliaries of the rotating machines is in some circumstances critical since it requires accessing the machine support platform.
FIGS. 1A and 1B illustrate different isometric views of a turbogenerator skid including baseplate and relevant rotating machinery and auxiliaries arranged thereon according to the current art. FIG. 2 illustrates a top view of the turbogenerator skid of FIGS. 1A, 1B. In this exemplary embodiment of a current arrangement, a gas turbine 101 is supported on a baseplate 103, and drives into rotation an electric generator 105. The gas turbine 101 is usually arranged within a turbine acoustic enclosure 102, which is removed in FIGS. 1A, 1B and shown only in FIG. 2. The gas turbine 101 comprises an inlet plenum 107, a gas generator 109, a power turbine 111 and an exhaust gas collector 113. The power turbine 111 is connected through a shaft 115 and a gear box 117 to the load 105. On the opposite end of the gas turbine 101 electric control panels 119 are arranged. Between the electric control panels 119 and the inlet plenum 107 a starter 121 is arranged. The starter 121 usually comprises an oil pump (visible in the drawing) which delivers oil under pressure to a hydraulic starter motor (not shown) which drives the gas turbine shaft into rotation before ignition of the fuel mixture.
The rotating machinery comprised of the gas turbine 101 and the electric generator 105 is arranged on the baseplate 103, the length L whereof is determined by the axial length of the rotating machines arranged thereon with all auxiliary systems. The width W of the baseplate 103 is determined by the transverse dimensions of the rotating machines as well as by the dimensions of the auxiliary devices and components, which must be mounted on and supported by the baseplate 103. Among those auxiliary devices, in FIGS. 1A, 1B and 2 the following are shown: the starter 121, as mentioned above; a fuel skid 125, arranged adjacent the gas turbine 101 inside the gas turbine acoustic enclosure 102; lubrication oil electric pumps 127; vapor separator for the oil tank 129; heat exchangers 131 for cooling the lubrication oil; lubrication oil filters 133; a lubrication oil tank arranged under the gear box 117 and the oil pumps 127.
The baseplate or skid 103 is comprised of a base frame formed by longitudinal beams 135 and cross beams 137 welded together to form a structure capable of supporting the static and dynamic loads generated by the rotating machines arranged on the baseplate 103.